(Supreme Court Justice Elena Kagan thought she scored some points when she demanded that the lawyer defending California’s Proposition 8 tell her the exact “harm” gay marriage would cause.) Of course, the point is that we don’t know how such a social experiment will turn out, or what specific “harm” will follow, no more than we know the benefits.Why would same-sex marriage, virtually unknown among human societies, be a “human right,” but polygamy, extensively documented in history and prevalent today all over the world, wouldn’t? Even the ancient Greek celebrator of homoerotic attraction, Plato, called sex between males “against nature.” No more scientifically based are the alleged “studies” that purport to show that children reared by gay couples suffer no adverse effects. As Nelson Lund writes in the Wall Street Journal, professional organizations like the American Psychological Association and the American Academy of Pediatrics claim that scientific research shows no differences between children growing up with gay couples and those raised by heterosexual parents, a claim parroted recently on NPR. But these studies are riddled with compromising flaws such as tiny nonrandom samples, a lack of control groups, and reliance on self-report from gay parents, no more an objective source of information than straight parents’ estimations of their parenting skills. Moreover, the most comprehensive study that did use a large randomized sample found several disadvantages for children raised in a household where parents were involved in a gay relationship. But as Lund reports, this study “has been vociferously attacked on methodological grounds by the same organizations that tout the value of politically congenial research that suffers from more severe methodological shortcomings.”(MORE)

(Answering the Stupid Question: how will gays marrying affect your marriage?)Nearly 40% of all births are to unmarried women. The rate in the Hispanic and Black communities is twice that. According to the CDC In 2007, 93% of births to 15–17 year-olds and 82% of births to 18–19 year-olds were nonmarital. Re-defining marriage by polygamy could absorb large numbers of unmarried single mothers. As men marry multiple times, providing male role models to millions of boys lacking that today.